Sensor-Like LC-MS Platform for Rapid Online Monitoring of Metabolites in Biological Systems

Project Summary Our research program focuses on the development of analytical tools to enhance the characterization of complex biological systems. For rapid, real-time analysis of these systems, sensors based on spectroscopic, electrochemical, and mass spectrometric detection have been widely utilized. However, the capability of these

approaches to simultaneously monitor multiple analytes suffers without the use of chemical separations. To achieve sensor-like performance with a separations-based platform, this project focuses on the creation of a liquid chromatography-mass spectrometry (LC-MS) platform for near-universal, real-time online measurement

of targeted small molecule metabolites. High-throughput gradient LC separations at capillary-scale flow rates will be achieved through system miniaturization and improved microfluidic mixing combined with a droplet-based injection approach. Improved analyte selectivity and sensitivity for targeted metabolites will be achieved with an

online benzoyl chloride derivatization device. To improve the temporal resolution of sampling, the derivatization technique will be adapted to a segmented flow droplet format. Dual column re-equilibration will further increase throughput by 20%, achieving an overall method cycle time of 10-15 s. By combining these fundamental

advances in separation science, a transformational measurement platform will be achieved. The system will be used to specifically probe: (1) neurotransmitter release from organoid cell models of traumatic brain injury, (2) polyamine secretion during bacterial biofilm formation, and (3) cell culture media nutrient depletion observed

during therapeutic antibody manufacturing.